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Message-ID: Date: Thu, 18 Aug 2022 16:12:10 +0200 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.12.0 Subject: Re: [PATCH] Use direct I/O for loop devices Content-Language: en-US To: Demi Marie Obenour Cc: Wei Liu , Anthony PERARD , =?UTF-8?Q?Marek_Marczykowski-G=c3=b3recki?= , Xen developer discussion References: <20220817204634.1886-1-demi@invisiblethingslab.com> <499daffa-b1c6-3868-c164-65335963922c@suse.com> From: Jan Beulich In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-ClientProxiedBy: FR3P281CA0155.DEUP281.PROD.OUTLOOK.COM (2603:10a6:d10:a2::16) To VE1PR04MB6560.eurprd04.prod.outlook.com (2603:10a6:803:122::25) MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: 6bd22a31-e9fa-4f3c-bbb7-08da8123a583 X-MS-TrafficTypeDiagnostic: VI1PR04MB4752:EE_ X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:VE1PR04MB6560.eurprd04.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230016)(366004)(376002)(39860400002)(396003)(136003)(346002)(41300700001)(478600001)(2906002)(6486002)(66556008)(66946007)(4326008)(8676002)(66476007)(8936002)(5660300002)(86362001)(186003)(31696002)(83380400001)(2616005)(6512007)(26005)(6506007)(53546011)(38100700002)(316002)(31686004)(36756003)(54906003)(6916009)(45980500001)(43740500002);DIR:OUT;SFP:1101; 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The old-ish one I'm looking at doesn't, >> according to its --help output at least. > > What version are you referring to? The tool itself doesn't recognize --version. It originates from util-linux 2.19.1 from all I can tell. > In Qubes OS the current plan is to use a block “script” written in C, to > improve performance and (when combined with kernel patches) eliminate > race conditions. This code could be made a wrapper for the C version. Is this relevant here in some way I don't recognize, or did you say this only to provide some further background info? Jan